Plunger



Nv. 12, 1929. E, w, F,HERRMANN 1,735,757

PLUNGER Filed Sept. 17, 1928 Ylllll l/l/m mm EL IIII/I INVENTOR wlmzsslzg Y E. W13 fierrmann BY ATTORNEY Patented Nov. 12, 1929 v I p I IT STATES ERNST W. F. HERRMANN, OF SAN ANTONIO,' TEXAS PLUNGER Application filed September 17, 1928. Serial-No. 306,377.

This invention relatesto plungers. v Referring more particularly to the draw- An object of the invention is the provision ings 1O designates a piston rod having a of aresiliently supported cup-shaped plunger threaded portion 11 which is received by a which may be of any suitable material for perforation in the metal disc 12 and a' perthe purpose, and in which the resilient memforation in a cup-shaped member 13. A 5 her is employed for maintaining the. shape spring retaining member 14 has a central pasof the material at all times. sage to receive the threaded portion 11 and Another object of the invention is the prois held against the inner face of the cup vision of a plunger vcup formed of leather or shaped member 13'by means of a nut 15 and some suitable composition material in which a nut 16.

is mounted a resilient member adapted to The plunger per se is cup shaped and is counteract the shrinkage orv deformation of formed of leather, rubber, or'some formof the cup, which is usually caused by heating composition material suitable for the purwhen the plunger is reciprocated within the pose and is provided with depending flanges cylinder, the resilient spring member being adapted to normally engagetheinner walls adapted to compensate shrinkage while reof the cylinder 21.

taining the walls of the cup member in neat The disc 14 is provided with a central pascontact with the walls of the cylinder. sage 22 to receive the threaded portion 11 of A further object I of the invention is the the rod 10 and has aplurality of cars 23 pro- 20 provision of a plunger in which a fieXible jecting radially from the periphery, The ears cup-sha ed member'cooperates' with a metal have inturned portions-24 forming lips to 'redisc to orm'a plunger, a continuous spring ceive the inner portions 25-of a plurality of member being supported in protective relaconvolutions 26 of a spring retaining memtion with the cup-shaped member for norber 27. p A

2 mally maintaining the flanged walls of the The spring retaining member is formed of said member in close association with the resilient wire and is bent to form a plurality walls-of the cylinder in which the plunger or of convolutions '26 which engage the inner piston is operated. face of the flan e 20 of the cup-shaped mem- This invention'will be best understood from her 13. Since t e diameter of the disc. 14is' 30 a consideration of the following detailed desomewhat less than the inner diameter of scription in connection with the accompanythe bottom of the cup-shaped member13, the ing drawings; nevertheless, it is to be underconvolutions 26 project outwardly and at an stood that the invention is not confined to the acute angle to the vertical, with thefree ends disclosure, being susceptible of such changes of the convolutions in engagement with the 35 and modifications as shall define no material inner face of the flange 20 for maintaining 5 departure from the salient features of the said flange in proper shape'and in contact invention as expressed in the appended claim, with the inner face of the wall of the cylinder in which in which the plunger is being operated. The

In the drawings ends of the spring member, as shown at 30,

4 Figure 1 is a View in elevation with parts are looped over one end of the ears 23 of the broken away and showing the application of inturned portion 24, and are bent inwardly my plunger to a pump, to maintain the spring member 27 in position Figure 2 is a bottom plan view of the plungon the supporting tongs of the disc 14. er constructed according to the principles of The plunger constructed according to the 4 my invention, principles of my invention is shown incor- Figure 3 is a transverse vertical section porated in an air pump for pneumatic tires taken along the line 3-3 of Fig. 2, I in Fig. 1, in which a handle 32 is employed Figure 4 is a View in perspective of a metal for reciprocating the rod 10, and the piston member which supports the spring element 13. A tube 33 is connected with the discharge 7 50 of the plunger. v port at the base 34 of the pump for conducting the fluids from the cylinder 21 to some device adapted to be supplied with air. It Will be appreciated that the piston may be employed in any type of pump and that the spring retaining member Will maintain the cup-shaped member in position and will counteract excessive shrinking of the same.

A plunger comprising a metal disc, a cupshaped member formed of flexible material, means for securingthe disc and cup-shaped member together, a second disc Within the cup-shaped member, a corrugated resilient member supported by the second mentioned disc and engaging the Wall of the cup-shaped member, ears projecting from the second mentioned disc and provided With inturned members'to receive the convolutions of the resilient member.

ERNST W." 141. I-IERRMANN. 

